Web guider

ABSTRACT

A web guider comprising a movable section that has an inlet roller for picking up a web, an outlet roller for releasing the web, and a curved rail; and a fixed section that has a guider for guiding the curved rail and a motor for providing a driving force for swinging the movable section; wherein the motor transmits the driving force through a driver of the motor to a follower of the curved rail, an orientation of the movable section is changed by changing a position at which the driver contacts the follower.

BACKGROUND OF THE INVENTION

[0001] 1.Field of the Invention

[0002] The present invention relates to a web guider capable ofcorrecting the path along which a web is transferred.

[0003] 2. Description of the Related Art

[0004] When a web is transferred, the web may be shifted toward oneedge, thereby shifting the center line of the web from the intendedpath. In such a case, the shift may be corrected by adjusting thetension on each edge of the web. A web guider known in the art guides aweb by a pair of rollers, and the orientation of the rollers withrespect to the web can be changed so as to correct the path of the web.For example, a web guider disclosed in European Patent Application No. 0092 735 corrects the shift of a web by swinging a pair of rollers with amale screw and a female screw meshing with each other.

[0005] However, with the straight male and female screws meshing witheach other, it is difficult to properly control the mechanism because ofthe low linearity between the amount by which the screws are turned andthe angle by which the rollers are swung.

SUMMARY OF THE INVENTION

[0006] The present invention has been made in view of the problem in theprior art, and has an object to provide a web guider that is easy tocontrol.

[0007] In order to achieve the object set forth above, the presentinvention provides a web guider, wherein: an inlet roller for picking upa web and an outlet roller for releasing the web are provided whilebeing spaced apart from each other; a portion of a side surface of eachof the pair of rollers is in contact with a surface of the web; amovable section for rotatably supporting the pair of rollers is providedswingably to a fixed section; a driving device for swinging the movablesection with respect to the fixed section is provided; an orientation ofthe pair of rollers with respect to the web is changed as the movablesection is swung; the driving device includes a curved rail for guidingthe swinging of the movable section, a driver for providing a drivingforce for swinging the movable section, and a follower for transmittingthe driving force from the driver to the movable section, the followerhaving a shape conforming to the curvature of the rail; and theorientation of the rollers is determined by a position at which thedriver contacts the follower.

[0008] As the orientation of the pair of rollers with respect to the webflow direction is changed by swinging the movable section, the tensionon each edge of the web changes. Thus, the web is moved along the axesof the rollers, thereby changing the path of the web being transferred.

[0009] On the other hand, the follower for transmitting the drivingforce from the driver to the movable section has a shape conforming tothe curvature of the rail, thereby providing an increased linearitybetween the amount by which the driver is driven and the angle by whichthe rollers are swung even if the swing angle of the rollers isincreased. Therefore, it is possible to easily and accurately controlthe swing angle of the rollers.

[0010] Moreover, the driving device includes a curved rail and afollower having a shape conforming to the curvature of the rail, wherebythe guider of the present invention can be made smaller, as comparedwith a case where a set of screws or a joint is used.

[0011] In the present invention, the inlet roller and the outlet rollermay be generally parallel to each other. Moreover, the length of eachroll may be greater than the width of the web, in which case it ispreferred that each end of the roll is extending past the correspondingedge of the web, so that the tension on each edge of the web can beadjusted.

[0012] The pair of rollers may be in surface contact with the same sideof the web, or may alternatively be in surface contact with the oppositesides of the web at remote positions so that the web is not sandwichedby the inlet roller and the outlet roller. Note that the inlet rollercomes into surface contact with any portion of the web, before theoutlet roller does.

[0013] The movable section maybe provided swingably with respect to thefixed section along the plane that includes the axes of the pair ofrollers. Alternatively, the movable section may be swingable along aplane that is inclined to, or that crosses, the plane, or may beswingable along a plane that is perpendicular to the plane including theaxes of the pair of rollers.

[0014] The rail may be curved along a line that is generally an arcwhose center is located closer to the inlet roller than to the outletroller. The term “arc” as used herein is not limited to a portion of acircle, but includes any other arc-like line, e.g., a portion of anellipse, a parabola, a hyperbola, a sine curve, a cycloid, etc.

[0015] The rail may be fixed to the movable section or to the fixedsection. When the rail is fixed to the movable section, a guided memberto be guided by the rail is provided on the fixed section. On the otherhand, when the rail is fixed to the fixed section, a guided member to beguided by the rail is provided on the movable section.

[0016] The driver and follower mechanism may be a mechanism including apinion and a curved rack, a worm and worm wheel mechanism, a screw gearmechanism.

[0017] The motor for swinging the frame may be fixed either to the fixedsection or the movable section. While the motor may be any of variousmotors or a solenoid, it is preferred that positional information on thepath of the web being transferred is detected by a detector, and theoperation of the motor is controlled according to the detection results.

[0018] In the present invention, am arm may be provided instead of therail for guiding the swing movement. For example, the base portion of aswingable arm may be attached to the fixed section while the movablesection is attached to the tip of the arm so that the movable sectionand the arm are swung integrally.

[0019] The detector detects a reference position of the web. Theopposing edges of the web are typically detected as “referencepositions”. Alternatively, when a graphical pattern or a picture isprinted on the web, it may be detected as a reference position andsubjected to an image processing operation so as to generate informationon the position of the web.

[0020] The means for detecting the reference position may be anultrasonic sensor, an optical sensor (e.g., an infrared sensor), an airsensor, etc. Alternatively, the deflection of the web may be detected byprocessing an image data obtained from a CCD camera or a linear sensor(line sensor).

[0021] A suitable type of a sensor can be selected depending on the typeof the web. For example, if an air easily passes through the web, it ispreferred to use an ultrasonic sensor or an optical sensor. If the webis transparent or semitransparent, it is preferred to use an ultrasonicsensor or an air sensor.

[0022] Note that the web may be any of various types of web, including awhole cloth for making a disposable worn article such as a disposablediaper, disposable pants, a sanitary napkin, or the like, a whole clothwith apertures, e.g., leg holes, therein, a whole cloth with an elasticmember adhered thereto, and a whole cloth with an absorbent layeredthereon.

BRIEF DESCRIPTION OF THE DRAWINGS

[0023]FIG. 1A is a perspective view illustrating a web guider accordingto one embodiment of the present invention, and FIG. 1B is a perspectiveview illustrating a first sensor.

[0024]FIG. 2A and FIG. 2B are a cross-sectional bottom view and across-sectional top view, respectively, illustrating the web guider.

[0025]FIG. 3A to FIG. 3C are schematic plan views illustrating a methodfor adjusting the path of a web.

[0026]FIG. 4A and FIG. 4B are cross-sectional side views eachillustrating the web guider.

[0027]FIG. 5 is a schematic diagram illustrating the configuration ofthe web guider.

[0028]FIG. 6A and FIG. 6B are plan views each illustrating a displayscreen of a display.

[0029]FIG. 7 is a schematic side view illustrating a variation of theembodiment of the present invention.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0030] An embodiment of the present invention will now be described withreference to the drawings. As illustrated in FIG. 1A, a web guider 2includes a movable section 5 and a fixed section 6.

[0031] The movable section 5 includes an inlet roller 30 for picking upa web W, and an outlet roller 31 for releasing the web W. The rollers 30and 31 rotatably attached to the movable section 5 while being spacedapart from each other by a predetermined interval. The web W runs aroundthe pair of rollers 30 and 31, and is released from the web guider 2while being in contact with each part of side surfaces of the inletroller 30 and the outlet roller 31.

[0032] As illustrated in FIG. 1A, each length of the rollers 30 and 31is set to be greater than the width Ww of the web W. On the other hand,the distance D between the outer edges of the pair of rollers 30 and 31is set to be ½ or more of the width Ww of the web W. Note that thedistance D between the outer edges of the pair of rollers 30 and 31 ispreferably equal to or greater than the width Ww of the web W. Therollers 30 and 31 are preferably made of a light material, e.g., analuminum alloy or a carbon graphite.

[0033] The movable section 5 illustrated in FIG. 1A can be rotated withrespect to the fixed section 6. The rotation of the movable section 5changes the orientation of the rollers 30 and 31 with respect to the webW, thereby correcting the path of the web W being transferred.

[0034] As illustrated in FIG. 2A and FIG. 2B, the movable section 5includes a rail 50 for changing the orientation of the movable section5. The rail 50 may be in an arc shape or a U-shape. When the rail 50 isin an arc shape, the movable section 5 is driven about the center O ofthe arc (FIG. 3A and FIG. 3B). In such a case, the rail 50 is curved soas to protrude toward the outlet roller 31.

[0035] In order to prevent the web W from being creased, it is preferredthat the center O is located closer to the inlet roller 30 than to theoutlet roller 31. Moreover, as illustrated in FIG. 3A, it is mostpreferred that the center O is located along one edge of the inletroller 30 that is away from the outlet roller 31.

[0036] In a case where the center O is located on one edge of the inletroller 30 that is away from the outlet roller 31 as illustrated in FIG.3A, as compared to a case where it is located at the center of the inletroller 30 as illustrated in FIG. 3B, the change in the position at whichthe web W is picked up is smaller, thereby better preventing the web Wfrom being creased.

[0037] As illustrated in FIG. 4A and FIG. 4B, the fixed section 6includes a plurality of guide rollers 62, a support section 60 forsupporting the guide rollers 62 and a motor M. The guide rollers (guidedmembers) 62 are rotatably attached to the support section 60. The rail50 is held between the guide rollers 62 for movement along a constantpath. Thus, the rail 50 can move between the guide rollers 62 under asmall frictional force. In the present embodiment illustrated in FIG. 2Aand FIG. 2B, the rail 50 is held by four guide rollers 62. With the rail50 being held by the guide rollers 62, the rail 50 can move along thepredetermined arc about the center O (FIG. 3A) without being shiftedsubstantially.

[0038] The motor M includes a driver 61 for providing a driving forcefor swinging the movable section 5. The driver 61 transmits the drivingforce from the motor M to a follower 51. The orientation of the rollers30 and 31 is determined by the position at which the driver 61 and thefollower 51 contact each other. The follower 51 may be provided withsubstantially the same location as the rail 50 with substantially thesame curvature.

[0039] Specifically, the follower 51, i.e., a rack 51 may be providedalong the rail 50, as illustrated in FIG. 2B. Moreover, the motor M maybe fixed to the support section 60, with a pinion (driver) 61 providedalong the output shaft of the motor M being engaged with the rack 51. Asthe pinion 61 is spun by the motor M, the rack 51 is moved, whereby themovable section 5 swings to the left and to the right about the centerO. Therefore, the orientations of the rollers 30 and 31 provided on themovable section 5 are determined accurately by the position of a gear(engaging portion) of the rack 51 that meshes with the pinion 61. Notethat the shape of the rack does not have to be straight, but mayalternatively be a curved shape, e.g., an elliptical shape, a parabolicshape, or an arc shape.

[0040] The motor M may be a stepping motor. By spinning the motor M, therollers 30 and 31 are swung by a predetermined angle. The predeterminedangle may be in the range of −20° to +20°.

[0041] Note that the rack 51 may be provided either on the protrudingside of the rail 50 or on the other side (i.e., the side closer to thecenter O). However, it is preferred that the rack 51 is provided on theprotruding side of the rail 50 in order to give a large torque on themovable section 5.

[0042] With the provision of the rack 51 along the rail 50, thelinearity between the amount by which the motor M is spun and the angleby which the movable section 5 is swung is increased, as compared with acase where a joint, or the like, is used. Therefore, even if the swingangle of the rollers 30 and 31 is large, it is possible to accuratelycontrol the swinging of the movable section 5.

[0043] Moreover, with the provision of the rack 51 along the arc-shapedrail 50, the swing angle of the rollers 30 and 31 can be increased, ascompared with a case where a joint, or the like, is used, as disclosedin U.S. Pat. No. 4,212,419. Thus, the swinging of the rollers 30 and 31can be controlled over a wide angle range, thereby allowing for asubstantial correction of the path of the web W. Furthermore, the guiderof the present invention can be made smaller, as compared with a casewhere a set of screws or a joint is used.

[0044] As illustrated in FIG. 5, the web guider 2 may include a sensorfor detecting a reference position of the web W, based on which the pathof the web W being transferred is defined, so as to output positionalinformation on the detected path, and a controller 10 for controllingthe spinning of the motor M based on the positional information from thedetector.

[0045] Specifically, the controller 10 may be a microcomputer includinga CPU 10 a and a memory 10 b. At least a first sensor (detector) 41, themotor M, and a display 7 to be described later are coupled with thecontroller 10 via an interface (not shown). Alternatively, the motor Mmay be controlled by the controller 10 based on instructions from anexternal controller.

[0046] It is preferred that the first sensors (detectors) 41 areprovided downstream of the outlet roller 31, and between the outletroller 31 and the next roller (not shown) downstream of the outletroller 31, as illustrated in FIG. 1A. This is because if the firstsensors (detectors) 41 are provided downstream of the next roller, themovement of the web W in the width direction is decreased. Note that itis more preferred that the first sensors 41 are provided at a positioncloser to the outlet roller 31 between the outlet roller 31 and the nextroller.

[0047] The first sensors 41 can detect the position of the web W. Theamount by which the web W is shifted can be determined by detecting anedge (reference position) of the web W with the first sensor 41, forexample.

[0048] The controller 10 illustrated in FIG. 5 has a manual mode inwhich the path of the web W is adjusted manually by the operator, and anautomatic mode in which it is adjusted automatically by the controller10 as will be described later.

[0049] In the automatic mode, the controller 10 may control the path ofthe web W as follows by using the pair of first sensors 41. For example,the first sensor 41 may include a light emitting section Sa for emittinglight and a light receiving section Sb for receiving light from thelight emitting section Sa, as illustrated in FIG. 1B.

[0050] One of the pair of first sensors 41 illustrated in FIG. 1Adetects one edge of the web W, and the other one detects the other edgeof the web W. In such a case, the path of the web W may be adjusted asfollows. That is, the controller 10 may control the path of the web W sothat the value of the detection signal (positional information) outputfrom one of the first sensors 41 is equal to that output from the otherone of the first sensors 41. When the path of the web W changes, i.e.,deflects to either side, the amount of light received by the lightreceiving section Sb changes according to the degree of the deflection.The controller 10 may control the spinning of the motor M based on thechange in the amount of received light.

[0051] For example, as illustrated in the conceptual diagram illustratedin FIG. 3C, when the web W is shifted to the left (the directionindicated by arrow L), the amount of light received by the left-sidefirst sensor 41 decreases while the amount of light received by theright-side first sensor 41 increases. According to the detection signalsfrom the first sensors 41, the controller 10 spins the motor M to swingthe rollers 30 and 31 clockwise as illustrated in FIG. 3A, therebymoving the path of the web W to the right (the direction indicated byarrow R).

[0052] Note that only one first sensor 41 may be provided, instead ofproviding a pair of first sensors 41, to detect only one edge of the webW. In such a case, the path of the web W can be adjusted as follows,assuming that the first sensor 41 is an optical sensor.

[0053] (1) The operator performs a predetermined operation to record, inthe controller 10, a value L_(MAX) of the detection signal that isoutput from the light receiving section Sb of the first sensor 41 whenthe light receiving section Sb is not covered by the web W at all.

[0054] (2) Then, a value L_(MIN) of the detection signal that is outputfrom the light receiving section Sb when the light receiving section Sbis completely covered by the web W is recorded in the controller 10.

[0055] (3) The controller 10 determines the display range of thedetection signal based on the recorded values L_(MAX) and L_(MIN). Thecontroller 10 can display the value of the signal output from the lightreceiving section Sb on the display 7 to be described later in thedetermined display range. The operator adjusts the position of the firstsensor 41 with respect to the web W so that the value of the detectionsignal becomes equal to the average value between L_(MAX) and L_(MIN) isobtained.

[0056] (4) The controller 10 outputs a control signal such that a levelL_(R) of an actual detection signal output from the light receivingsection Sb is between L_(MAX) and L_(MIN), and the motor M is spun basedon the control signal. For example, a value C of the control signal maybe obtained as shown in Expression (1) below:

C=A*(L _(R)-L _(STN))  (1)

[0057] where L_(STN) is the average value between L_(MAX) and L_(MIN),and A is a constant.

[0058] Although the light receiving section of an optical sensortypically has a round shape (for example, U.S. Pat. No. 5,300,787, U.S.Pat. No. 5,379,656, and U.S. Pat. No. 5,442,187), the light emittingsection and the light receiving section of the optical sensor mayalternatively has an oblong shape. It is preferred that the lightemitting section emits light having a desirable coherence. Poor phase orstraightness of light may become a disturbance that hinders theimprovement of the measurement accuracy. In view of this, a bundle ofoptical fibers may be provided so that the emitted light is passedtherethrough. Alternatively, the light emitting section may be dividedinto a plurality of regions so that light is emitted from the pluralityof regions successively at regular intervals, thereby avoidinginterference of light emitted from adjacent light emitting devices toimprove the measurement accuracy. Alternatively, light maybe emittedfrom the light emitting section via a filter capable of making theemitted light coherent. Note that emitted light does not have to bevisible light.

[0059] Moreover, the first sensor 41 may include a cleaner for cleaningthe light receiving section and/or the light emitting section. Forexample, a spec of dust attached to the light receiving section or thelight emitting section may be blown off with air by the cleaner. Forexample, the first sensor 41 illustrated in FIG. 1B may include anaperture 8 or a gap through which the air is blown in the direction inwhich the web W runs or in the opposite direction. The air is blowncontinuously or intermittently by the controller 10. In a case where theair is blown intermittently, the controller 10 may control the air blowso that the air is blown periodically or randomly. Note that if the airis blown through an aperture, or the like, an orifice effect isobtained.

[0060] The web guider 2 may further include the display 7. Specifically,the display 7 may be coupled with the controller 10 illustrated in FIG.5. The display 7 may be a liquid crystal display or a plasma display. Anoperation screen (FIG. 6A), a settings screen (FIG. 6B), etc., may bedisplayed on the display 7.

[0061] As illustrated in FIG. 6A, on the operation screen of the display7, an automatic mode button 70, a manual mode button 71, a left sensorbutton 72, a right sensor button 73, a setting button 74, shift amountdisplay areas 76, swing buttons 77, etc., are displayed. On the settingscreen illustrated in FIG. 6B, a numeric keypad 75, etc., are displayed.

[0062] The display 7 may be provided on the fixed section 6 illustratedin FIG. 1A, or separately from the fixed section 6. Note that it ispreferred that the display 7 is provided within 1.5 m from the webguider 2, which displays information of the first sensor 41. When thedisplay 7 is excessively remote from the web guider 2, and if a wireddata line is used, noise is likely to be introduced to the data line.Moreover, the display 7 may be a touch screen.

[0063] The controller 10 illustrated in FIG. 5 may measure the amount bywhich the rail 50 is moved. For example, the motor M may output apredetermined signal each time the motor M is spun by a predeterminedamount (e.g., a number of turns, which may be less than one), and thecontroller 10 may count the number of the predetermined signals, therebymeasuring the amount by which the rail 50 is moved. Alternatively, thecontroller 10 may determine the position of the rail 50 by detecting amark on the rail 50. For example, a second sensor for reading such amark put on the rail 50, and the controller 10 may receive positionalinformation from the second sensor. Particularly, the mark may indicatethe limit to which the movable section 5 can be swung. In such a case,the controller 10 may stop the spinning of the driving unit when thesecond sensor detects the limit.

[0064] The operation of the web guider, where optical sensors are usedas the pair of first sensors 41, will now be described.

[0065] First, the operation of the web guider 2 in an automatic modewill be described.

[0066] Before the operation in the automatic mode, the operatorcalibrates the first sensors 41. Note that once the calibration of theposition of the first sensors 41 is done, it does not have to beperformed again unless a web of a different width is used.

[0067] The first sensors 41 are operated to perform the detectionoperation while the web W is not passed around the rollers 30 and 31.Then, the web W is passed around the rollers 30 and 31, and the firstsensors 41 are moved to positions at which both edges of the web W canbe detected by the first sensors 41, according to the width Ww of theweb W. The operator calibrates the positions of the first sensors 41based on the positions of the edges of the web W displayed on the shiftamount display areas 76 illustrated in FIG. 6A.

[0068] The operator may perform a predetermined operation to have thesetting screen illustrated in FIG. 6B displayed, and change the presetinitial values by using the numeric keypad 75. On the setting screen,various settings can be changed, e.g., the sensor detection width, theshift upper limit, the dead zone, etc. The sensor detection width is avalue associated with the width of an edge of the web W to be detectedby the first sensors 41. The shift upper limit is a value based on whichthe motor M is controlled so that the corrected path of the web W is notbeyond the detection range of the first sensors 41. The dead zone is avalue representing the range (guiding point) in which the first sensors41 perform the detection operation.

[0069] Then, the operator touches the automatic mode button 70, and thesensor buttons 72 and 73 to initiate the transfer of the web W. Notethat in a case where only one of the pair of first sensors 41 is used,only one of the left and right sensor buttons 72 and 73 is touched.

[0070] According to the detection signals from the first sensors 41, thecontroller 10 spins the motor M to swing the rollers 30 and 31 to theleft and to the right to correct the path of the web W. For example,when the web W is shifted to the left as illustrated in FIG. 3C, thecontroller 10 spins the motor M so as to swing the rollers 30 and 31illustrated in FIG. 3A in the clockwise direction (i.e., a directionopposite to the direction in which the web W is shifted) to move thepath of the web W to the right. On the other hand, when the web W isshifted to the right, the rollers 30 and 31 are swung in thecounterclockwise direction (i.e., a direction opposite to the directionin which the web W is shifted) to move the path of the web W to theleft. The controller 10 repeatedly swings the rollers 30 and 31 tocorrect the path of the web W according to the detection signals fromthe first sensors 41.

[0071] Thus, the rollers 30 and 31 of the movable section 5 are swungaccording to the amount by which the web W is shifted, which is detectedby the first sensors 41, and the tension on each edge of the web W iscontrolled by the rollers 30 and 31, thereby correcting the path of theweb W.

[0072] As necessary, the operator operates the web guider 2 in themanual mode. As the operator touches the manual mode button 71 on thedisplay 7, the CPU 10 a is set in the manual mode. The operator touchesthe right or left swing button 77 to swing the rollers 30 and 31 so asto correct the path of the web W.

[0073] Note that the web W may be passed around the rollers 30 and 31 inan N- or S-shaped pattern as illustrated in FIG. 7.

[0074] As described above, according to the present invention, thefollower for transmitting the driving force from the driver to themovable section has a shape conforming to the curvature of the rail,thereby providing an increased linearity between the angle by which therollers are swung and the amount by which the driver is driven even ifthe swing angle of the rollers is increased. Therefore, it is possibleto easily and accurately control the swing angle of the rollers.

[0075] Particularly, with the center about which the movable section isswung being located closer to the inlet roller than to the outletroller, the displacement of the inlet roller, occurring when theorientation of the inlet roller is changed, can be reduced, therebyreducing the creasing of the web.

[0076] Moreover, with the provision of a guide rail curved in an arcshape, the swinging of the movable section can be realized simply andreliably.

[0077] Moreover, if the shift in the path of the web is detected, andthe motor is controlled based on the detection output, so that the shiftcan be corrected automatically, the web guider can run in a continuous,automated operation.

[0078] Furthermore, if the detected shift amount of the web is displayedon the display, the position at which to place the detector can be knowneasily, thereby significantly facilitating the operation and maintenanceof the apparatus.

[0079] Moreover, since the web is transferred along a generally U-shapedpath, the motor, etc., can be placed in the space inside the generallyU-shaped path, thereby improving the space efficiency. Furthermore, ifthe operation section is provided on one side of the space, operationssuch as an initial setting operation can be performed while visuallyobserving the shift of the web, thereby significantly improving theoperability of the web guider with respect to the various settingoperations.

What is claimed is:
 1. A web guider, comprising: a movable section thathas an inlet roller for picking up a web, an outlet roller for releasingthe web, and a curved rail; and a fixed section that has a guider forguiding the curved rail and a motor for providing a driving force forswinging the movable section; wherein the motor transmits the drivingforce through a driver of the motor to a follower of the curved rail,and wherein an orientation of the movable section is changed by changinga position at which the driver contacts the follower.
 2. The web guideraccording to claim 1, wherein the driver and the follower are providedwith an engaging portion for preventing slipping therebetween.
 3. Theweb guider according to claim 2, wherein a center about which themovable section is swung is located closer to the inlet roller than tothe outlet roller.
 4. The web guider according to claim 3, wherein therail is curved along a line that is generally an arc.
 5. The web guideraccording to claim 1, wherein a length of each of the inlet roller andoutlet roller is greater than a width of the web, and a distance betweenouter edges of the inlet and outlet rollers is set to be ½ or more ofthe width of the web.
 6. The web guider according to claim 2, wherein alength of each of the inlet roller and outlet roller is greater than awidth of the web, and a distance between outer edges of the inlet andoutlet rollers is set to be ½ or more of the width of the web.
 7. Theweb guider according to claim 3, wherein a length of each of the inletroller and outlet roller is greater than a width of the web, and adistance between outer edges of the inlet and outlet rollers is set tobe ½ or more of the width of the web.
 8. The web guider according toclaim 4, wherein a length of each of the inlet roller and outlet rolleris greater than a width of the web, and a distance between outer edgesof the inlet and outlet rollers is set to be ½ or more of the width ofthe web.
 9. The web guider according to claim 1, further comprising: adetector for detecting a reference position of the web, based on which apath of the web is defined, the detector configured to output positionalinformation associated with the defined path; and a controller forcontrolling the motor for swinging the movable section based on thepositional information.
 10. The web guider according to claim 2, furthercomprising: a detector for detecting a reference position of the web,based on which a path of the web is defined, the detector configured tooutput positional information associated with the defined path; and acontroller for controlling the motor for swinging the movable sectionbased on the positional information.
 11. The web guider according toclaim 3, further comprising: a detector for detecting a referenceposition of the web, based on which a path of the web is defined, thedetector configured to output positional information associated with thedefined path; and a controller for controlling the motor for swingingthe movable section based on the positional information.
 12. The webguider according to claim 4, further comprising: a detector fordetecting a reference position of the web, based on which a path of theweb is defined, the detector configured to output positional informationassociated with the defined path; and a controller for controlling themotor for swinging the movable section based on the positionalinformation.
 13. The web guider according to claim 5, furthercomprising: a detector for detecting a reference position of the web,based on which a path of the web is defined, the detector configured tooutput positional information associated with the defined path; and acontroller for controlling the motor for swinging the movable sectionbased on the positional information.
 14. The web guider according toclaim 9, wherein: the detector is operable to detect an amount by whichthe web is shifted in a width direction of the web; and the web guiderfurther comprises a display for displaying the shift amount.
 15. The webguider according to claim 10, wherein: the detector is operable todetect an amount by which the web is shifted in a width direction of theweb; and the web guider further comprises a display for displaying theshift amount.
 16. The web guider according to claim 11, wherein: thedetector is operable to detect an amount by which the web is shifted ina width direction of the web; and the web guider further comprises adisplay for displaying the shift amount.
 17. The web guider according toclaim 12, wherein: the detector is operable to detect an amount by whichthe web is shifted in a width direction of the web; and the web guiderfurther comprises a display for displaying the shift amount.
 18. The webguider according to claim 13, wherein: the detector is operable todetect an amount by which the web is shifted in a width direction of theweb; and the web guider further comprises a display for displaying theshift amount.
 19. The web guider according to claim 9, wherein: anoperation section with which the controller is operated is provided onone side of the fixed section.
 20. The web guider according to claim 10,wherein: an operation section with which the controller is operated isprovided on one side of the fixed section.
 21. The web guider accordingto claim 11, wherein: an operation section with which the controller isoperated is provided on one side of the fixed section.
 22. The webguider according to claim 12, wherein: an operation section with whichthe controller is operated is provided on one side of the fixed section.23. The web guider according to claim 13, wherein: an operation sectionwith which the controller is operated is provided on one side of thefixed section.
 24. A web guider apparatus, comprising: a moveablesection comprising an inlet roller operable to pick up a web, an outletroller operable to release the web, and a curved rail, wherein thecurved rail further comprises a follower, and wherein a curvature of thefollower is associated with a curvature of the curved rail; and a fixedsection comprising a plurality of guide rollers, a motor, and a driver,wherein the driver is in operable engagement with the follower, whereinthe motor is operable to provide a driving force to the driver, whereinthe moveable section is operable to rotate with respect to the fixedsection, wherein the rotation of the moveable section is substantiallylinearly proportional to the driving force, and wherein the plurality ofguide rollers are operable to guide the curved rail along apredetermined path associated with the curvature of the curved rail. 25.The web guider apparatus of claim 24, further comprising an engagingportion associated with the driver and the follower, wherein slippage isgenerally prevented between the driver and the follower.
 26. The webguider apparatus of claim 25, wherein the follower comprises a rack andthe driver comprises a pinion.
 27. The web guider apparatus of claim 24,wherein the rotation of the moveable section with respect to the fixedsection is along a generally arc-shaped line.
 28. The web guiderapparatus of claim 24, wherein the moveable section is rotated about acenter point associated with the fixed section, and wherein the centerpoint is located closer to the inlet roller than the outlet roller. 29.The web guider apparatus of claim 28, wherein the center point islocated along an edge of the inlet roller that is farthest from theoutlet roller.
 30. The web guider apparatus of claim 24, wherein alength of the inlet roller and the outlet roller is greater than a widthof the web, and wherein a distance between an outer edge of the inletroller and an outer edge of the outlet roller is at least one half ofthe width of the web.
 31. The web guider apparatus of claim 24, furthercomprising: a detector operable to detect a reference position of theweb, the detector further being configured to output positionalinformation associated with a path of the web, wherein the path of theweb is defined by the detector based on the reference position; and acontroller operable to control the motor, wherein the driving force iscontrolled based on the position information.
 32. The web guiderapparatus of claim 31, wherein the reference position comprises aposition of an edge of the web.
 33. The web guider apparatus of claim31, further comprising a display, wherein the detector is operable todetect an amount by which the web is shifted in a width direction of theweb, and wherein the display is operable to display the shifted amount.34. The web guider apparatus of claim 33, wherein the display furthercomprises an operation screen, wherein the operation screen is operableto provide operator input to the controller.
 35. The web guiderapparatus of claim 34, wherein the operation screen is located on oneside of the fixed section.